One of the biggest issues involved in insulating a property is with the doorway. Whenever you open it, you are automatically letting a portion of heat stored in the property out of it, but this is unavoidable; all you can hope to do is to limit the amount of heat-loss when the door is closed.
A number of factors come into play when considering insulating a doorway, but one of the biggest is definitely the draft. This draft is only present because the door doesn’t fit the entrance completely, forming an imperfect seal. While this can be corrected to an extent by properly shaping and designing the door, buying a draft excluder will always be a valuable purchase.
Another factor in the insulation factor of the door will be the materials used to make it. Depending upon the material and the thickness of it, you will, of course, get differing levels of effectiveness. Using a layered style of design will allow you to have the aesthetics you want for your door with an invisible layer of super insulating materials.
Lastly, something which a lot of people forget about, you should always make sure that your letterbox is also well insulated, as this can significantly contribute to heat-loss in a home.